A distribution service for video telephones is known from the ITU-T recommendation H.331. More precisely, it defines the functionality of the distribution service (broadcast service). Such a distribution service establishes the coding process whereby the video and audio signals are encoded. The signalling parameters are established as well.
A so-called video phone server is also known in the state of the art. This ISDN server offers a number of services to a caller. A caller calls the ISDN server via a conventional ISDN-H.320 video phone and is able to select information. Up to 1000 different services are offered in this case. This video phone server provides 9.times.2 B-channels.
The function of storing the incoming information is also known. In this case a TV program to be currently transmitted is stored and can be transmitted with time-delay. Accordingly a caller can either request previously stored messages or call up messages that were transmitted in real time.
A larger version of this video telephone server may contain 15.times.2 channels. A disadvantage of such a server is that only 30 video phones can access the server at the same time, and that only video telephones which operate in accordance with the H.320 standard are able to access this server (from: Interactive Video Telephony by Prospects of the Telsis Company, Copyright 1995 Telsis, received via CeBit '96).